In order to feed single sheets, for example of paper, from a stack of sheets, it is necessary to separate the sheets from one another. Typically this is done by extending a portion of the frame of the sheet feeder at positions corresponding to two of the corners on the leading edge of the uppermost sheet within the stack of sheets, so that the frame slightly overlaps these two corners. This structure, often referred to as corner nips, cause the uppermost sheet to buckle when it is driven forward by the feed means of the sheet feeder. Ideally this buckling separates the uppermost sheet from the sheets adjacent to it. Corner nips, however, are not 100% effective, and due to such phenomena as static electricity, adjacent sheets often cling together in spite of the action of the corner nips. Manufacturers therefore often instruct the users of sheet feeders to manually fan or shuffle one edge of the stack of sheets prior to inserting the sheets into the sheet feeder. This fanning helps to separate the various sheets from one another, and thus assist the corner nips in their function of separating the sheets.